Granted Patent
Utility
US 5,728,202 · App. 08/712,324
Gilsonite modified, natural, hydrocarbon-enriched sand composition
Inventors:
Roy E. Nelson, Michael Nuzzolo, Kenneth Clark Christensen
Patented Case
View Patent ↗
Granted: Mar 17, 1998
Filed: Sep 11, 1996
Inventors
Roy E. Nelson
Michael Nuzzolo
Kenneth Clark Christensen
Assignee (at issue)
AMERICAN GILSONITE COMPANY
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.